Bystra kusukusensis (Uchida, 1929)

Bystra kusukusensis (Uchida, 1929) View in CoL

( Figs 24–28 View FIGURES 24–28 )

Material. [ Japan] Kagoshima Pref.: Yakushima Isl. , Malaise trap ( AN 3, 170 m alt.), 2 ♂♂ 22. VII. – 22. VIII. 2006, T. Yamauchi et al. leg . ( Kanagawa);

Description. Male. Body length 14.0– 14.5 mm. Length of fore wing 12.0–13.0 mm.

Head. Flagellum with 41 flagellomeres, bristle-shaped; 1 st flagellomere 2.9–3.1× as long as wide, distal flagellomeres slightly nodose. Tyloids on flagellomeres 10–13, linear, maximally 0.5× as long as their flagellomeres. Temple short, strongly and roundly narrowed behind eye. OED 1.2× and OOD 0.8× ocellar diameter. Frons finely shagreened. Face densely punctate. Clypeus densely punctate, slightly convex; apical margin blunt and straight. Anterior tentorial pit large. Ventral mandibular tooth much smaller than dorsal tooth and moderately bent inwards (by 45°). MI 0.7. Gena with rather dense punctures. Genal carina reaching hypostomal carina away from mandibular base, both carinae low.

Mesosoma . Notaulus impressed in frontal 0.2 of mesoscutum. Mesoscutum densely punctate and shagreened, dull. Mesopleuron and metapleuron densely but superficially punctate, shining. Speculum largely smooth. Juxtacoxal carina present in frontal half of metapleuron, indicated by some irregular rugae posteriorly. Scutellum slightly elevated, slightly longer than wide, with rather dense punctures and with lateral carina in basal 0.7. Propodeum coarsely punctate. Area basalis with distinct median tubercle. Area superomedia hexagonal, about as long as wide; costula reaching its middle. Hind femur 4.0–4.3× as long as wide. External surface of hind tibia with multiple fine spines. Areolet quadrangular and almost pointed frontally; vein 2m-cu slightly distal to its middle. Vein 1cu-a slightly antefurcal by 1.0× its width.

Metasoma. Postpetiole moderately widened, without latero-median carina, median field not separated, finely shagreened and ± shining, lateral field with sparse punctures. Gastrocoelus impressed, with coarse rugae. Thyridium transverse, 0.4–0.5× as wide as interval between thyridia. 2 nd tergite about as long as wide, with weak diffuse lateral impression (as in Losgna ). 2 nd and 3 rd tergites densely punctate and granulate, dull. Apical margin of hypopygium moderately and roundly elongate medially.

Color . Red. Flagellomeres 1–12 red, flagellomeres 13–18/19 yellowish, following flagellomeres black. Palps, mandible except teeth, clypeus, face, gena and frontal orbit up to lateral ocellus yellowish. Mesoscutum with three reddish-brown longitudinal stripes. Frontal and upper margins of pronotum, subtegular ridge and postscutellum yellowish. Mesopleuron ± reddish-yellow ventrally. Tergite red; 2 nd and 3 rd tergite with diffuse yellowish apical margins. Legs red; fore and mid coxae and trochanters cream-yellow. Wings slightly infuscate, pterostigma yellowish.

Distribution. Japan (Yakushima Isl.), China, Korea and Taiwan. New record for Japan.

Remarks. The males from Yakushima differ from the original description of Bystra kusukusensis (Uchida, 1929) by a completely red stemmaticum and red hind leg. The presence of weak impressions of 2 nd tergite resembles the genus Darymna Cameron but we do not formally transfer this species to Darymna here since the taxonomy of the Oriental genera of the Ichneumoninae related to Bystra needs a comprehensive modern revision.